May I submit a revised income tax return for 2008-09 to include the arrears payment of 2008-09 received in 2009-10. If so, under what rules and how can I do that? What is the minimum annual income for the year 2009-10 for which there is no income tax for senior citizens? 
 
ce you have received the arrears payment in 2009-10, you shall have to show the income in the return for 2009-10 only. You dont have to file a revised return for 2008-09. The basic exemption limit of income for senior citizens for 2009-10 financial year is Rs 2.40 lakh.
 
Hike in pension 

I am a pensioner and I am entitled to a hike of 20 per cent of the basic pension on attaining the age of 80 years as recommended by the Sixth Pay Commission. Since my date of birth is March 16, 1931, I would seek clarifications as to the date/month from which I shall be considered to have attained the age of 80 years so that I can avail of the enhanced pension claim.
 
Your date of birth is March 16, 1931. So on March 15, 2010 you had completed 79 years and from March 16, 2010 you have attained 80 years.
 
Buying a house

I am a state government employee. In order to purchase a resale flat, I have paid Rs 25,000 in advance payment through a demand draft to the individual seller. Is the amount deductible from gross total income under Section 80C of the Income Tax Act?
  
case of purchasing a house, the benefit of deduction applies only when you take a loan to fund the purchase. Furthermore, the deduction can be availed of only after taking the possession of the property and not before that. When it comes to home loan, principal payment up to Rs 1 lakh is deductible under Section 80C of the Income Tax Act. So, when you buy a house property, you wont get any deduction benefit for the amount you pay on your own as down payment or booking advance.